Simulating eye surgery

ABSTRACT

A reusable surgical model of the eye has mating anterior and posterior segments. The posterior segment has structures corresponding to those of the eye, including a hollow globe and an image of the fundus positioned upon an interior, posterior portion of the globe. A mating connector is peripherally formed about an open end of the globe. The anterior segment includes structures corresponding to those of the eye, including a pars plana, an opening in a region corresponding to an iris, and a lens positionable within the opening. The anterior segment has a peripheral connector which mates with that of the posterior segment. The lens is removably connected to the anterior segment, and has a focal length corresponding to a natural eye. A coating is applied to the fundus to enable simulation of a membrane peeling procedure, and the globe is fillable with a vitreous substitute.

FIELD OF THE DISCLOSURE

The disclosure relates to a system and method for simulating the eye,and in particular, to a physical model which can be used to simulatesurgical procedures.

BACKGROUND OF THE DISCLOSURE

Many surgical techniques requires dexterous movement and control by thesurgeon. This dexterity cannot be developed by reading textbooks orwatching instructional videos. Animal models or cadavers have been thedefault method for hands-on surgical training. In the field ofophthalmic surgery, there are simple examples of a cataract surgerymodel.

Advances in 3D printing technology allow for the creation of structureswith discrete regions having customized mechanical properties. It ispossible to print a single object that contains hard components orregions, soft components or regions, and components and regions withproperties in-between. This is achieved by the simultaneous depositionof two complementary materials, one soft and one hard, in controlledproportions, in specific 3D coordinates.

SUMMARY OF THE DISCLOSURE

A device of the disclosure enables simulating surgery upon the eye, andcomprises a posterior segment including: structures corresponding tothose of the eye, including a hollow globe and an image of the funduspositioned upon an interior, posterior portion of the globe; and a firstmating portion peripherally formed about an open end of the globe; ananterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens positionable within the opening; a second matingportion peripherally formed about a posterior portion of the anteriorsegment, the second mating portion mateable with the first matingportion to releasably connect the posterior and anterior segments; athird mating portion peripherally formed about the lens; and a fourthmating portion peripherally formed about the opening, the fourth matingportion mateable with the third mating portion to releaseably connectthe lens and the anterior portion.

In variations thereof, the first, second, third, and fourth matingportions are dovetail portions; the device further includes a pluralityof rectus muscles each attached to the globe at attachment points; oneor more of the plurality of rectus muscles overlapping the anteriorsegment to retain the anterior segment in mating connection to theposterior segment; the device further includes a base, the base attachedto the plurality of rectus muscles; the globe is at least partiallyoptically transparent; the device is fabricated using a multi-material3D printing process; and/or the lens is releasably retained between thethird mating portion and a structure resembling ciliary bodies.

In further variations thereof, the device further includes a removablecoating applied to an interior of the posterior segment; the coating isa liquid which is applyable to the fundus to form a film that willadhere to the fundus when dried, and after drying is peelable from thefundus in strips; the coating includes a substrate and a volatilesolubilizing agent; and/or the coating is contained within a roll-onapplicator.

An accordance with the disclosure, a method of enabling simulation oftherapeutic procedures performed upon the eye, comprises providing aposterior segment including: structures corresponding to those of theeye, including a hollow globe and an image of the fundus positioned uponan interior, posterior portion of the globe; and a first mating portionperipherally formed about an open end of the globe; providing ananterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens positionable within the opening; a second matingportion peripherally formed about a posterior portion of the anteriorsegment, the second mating portion mateable with the first matingportion to releasably connect the posterior and anterior segments; athird mating portion peripherally formed about the lens; and a fourthmating portion peripherally formed about the opening, the fourth matingportion mateable with the third mating portion to releaseably connectthe lens and the anterior portion; providing a coating which isapplyable to the fundus to form a film that will adhere to the funduswhen dried, and after drying is peelable from the fundus in strips.

In variations thereof, the coating provided includes a substrate and avolatile solubilizing agent; the method further includes providinginstructions for applying the coating to the posterior segment; thesubstrate is selected from a cellulosic and a polymeric material; thecoating is provided in a roll-on applicator; the method further includesproviding a vitreous substitute material to be placed inside theposterior segment; and/or the method further includes providinginstructions for inserting a vitreous substitute material into theposterior segment.

In accordance with a method of the disclosure, simulating a surgicalprocedure upon the eye comprises separating an anterior segment of asimulated eye from a posterior segment segment of a simulated eye, theposterior segment including: structures corresponding to those of theeye, including a hollow globe and an image of the fundus positioned uponan interior, posterior portion of the globe; and a first mating portionperipherally formed about an open end of the globe and having the formof one of an annular groove and annular flange;

the anterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens; a second mating portion peripherally formed about aposterior portion of the anterior segment, the second mating portionmateable with the first mating portion to releasably connect theposterior and anterior segments, the second mating portion having theform of an annular groove if the first mating portion is an annularflange, and an annular flange if the first mating portion is an annulargroove; inserting a vitreous substitute material into the posteriorsegment, the substitute material resembling the viscosity and appearanceof vitreous humor of a natural eye; and simulating a surgical procedureincluding removal of vitreous substitute from the eye with the posteriorand anterior segments assembled together.

In a variation thereof, the method further includes, prior to insertinga vitreous substitute, applying a coating to a portion of the image ofthe fundus; and simulating a surgical procedure including peeling of thecoating with the posterior and anterior segments assembled together.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a side perspective view of an eye model of the disclosure;

FIG. 2 is an exploded view of the model of FIG. 1;

FIG. 3 is a front view of the model of FIG. 1;

FIG. 4 is perspective view of the model of FIG. 1, with the anteriorsegment removed;

FIG. 5 is a longitudinal cross-section through the model of FIG. 1;

FIG. 6 is a removable fundus positionable within the model of FIG. 1;

FIG. 7 is a flexible substrate printed with an image of the fundus,positionable within the model of FIG. 1;

FIG. 8 is an anterior perspective view of the anterior segment of themodel of FIG. 1;

FIG. 9 is a front perspective view of the anterior segment of the modelof FIG. 1;

FIG. 10 is a cross-section through a center of the anterior segment ofthe model of FIG. 1, with the lens removed;

FIG. 11 depicts a manner of coating a fundus area of the model of FIG.1;

FIG. 12 depicts a manner of manipulating the model of FIG. 1 with asurgical instrument;

FIG. 13 depicts peeling of the coating of FIG. 11 using the instrumentof FIG. 12;

FIG. 14A depicts assembly of the anterior segment onto the model of FIG.1, initially laterally moving the anterior segment under two muscleattachments;

FIG. 14B depicts a further assembly step, subsequent to the step of FIG.14A, in which the anterior segment is positioned under three muscleattachments;

FIG. 14C depicts compressing the model in order to expose a portion ofthe fourth muscle attachments, in order to facilitate moving the fourthmuscle attachment above the anterior segment;

FIG. 15 depicts filling the posterior segment of the model of FIG. 1;and

FIG. 16 depicts removing a vitreous substance from within the model ofFIG. 1.

DETAILED DESCRIPTION OF THE DISCLOSURE

As required, detailed embodiments are disclosed herein; however, it isto be understood that the disclosed embodiments are merely examples andthat the systems and methods described below can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present subject matter in virtually anyappropriately detailed structure and function. Further, the terms andphrases used herein are not intended to be limiting, but rather, toprovide an understandable description of the concepts.

The terms “a” or “an”, as used herein, are defined as one or more thanone. The term plurality, as used herein, is defined as two or more thantwo. The term another, as used herein, is defined as at least a secondor more. The terms “including” and “having,” as used herein, are definedas comprising (i.e., open language). The term “coupled,” as used herein,is defined as “connected,” although not necessarily directly, and notnecessarily mechanically.

The disclosure provides a device 100 which duplicates certain featuresof a human eye, or the eye of other organisms which are similar to thehuman eye. The device, having certain features of an anatomical model,mimics or is similar in appearance and mechanical properties to the eyeand associated structures, and can be used to understand eye pathology,and for surgical training, demonstration, teaching aids, surgicalinstrument calibration, validation, and research and development. Device100 may also be used together with other models for craneo-facialsurgery, as a crash test dummy component, or as a ballistic impactmodel, for example.

Device 100 replicates the mechanical properties of tissues of the eye.More particularly, except for fluid connective tissue, such as blood andlymph, a tissue matrix of the body can be mechanically simplified asbeing made of two materials, collagen and elastin. Collagen is thematerial that confers strength, and elastin is the material that conferselasticity. The proportion of elastin and collagen type fibers in thematrix of a tissue can be related to its mechanical properties. Tissuestructures predominantly composed of collagen tend to be tough andrigid. Tissue where elastin predominates is more elastic.

As discussed in greater detail in U.S. Patent Pub. 2016/0372011 and U.S.Pat. No. 9,437,119, the contents of which are incorporated herein byreference, the inventor has found that the an eye model can be producedby 3D multi-material printing, whereby different tissues of the eye canbe represented by particular materials during printing. In this manner,the texture and appearance of the particular structures can bereproduced within the model. As one example, as discussed elsewhereherein, a trocar is inserted into the anterior portion of the eye. Theanterior segment of device 100 is fabricated using a material whichresponds in a similar manner to eye tissue, when pierced by a trocar,for example yielding in a similar manner, and retaining an access portin a similar manner.

For example, the eye can conveniently be considered as being composed ofcollagen type tissue, and elastin type tissue, where a differentmaterial can be used to produce each type of tissue. However, regardlessof how various tissues in the eye are classified with respect tocollagen or elastin, materials printed are ultimately selected to have ahardness and resiliency which mimics structures of the natural organ.More particularly, materials are selected whereby the resultant tissuesimulation behaves in a manner similar to a live or donor eye, withrespect to resistance to pressure, piercing and cutting,burning/ablation, manipulation, and other applications of force, as wellas physical appearance. The 3D printed materials, or materials used inother types of manufacturing processes, are therefore selected to bestrepresent the properties of the tissue to be reproduced in device 100.

While 3D printing is one method to device 100, it should be understoodthat other manufacturing methods can be used, including casting,molding, machining, and other known or hereinafter developed methods.

With reference to FIGS. 1-3, device 100 includes a support base 102, aposterior segment 110 including an area corresponding to the ora serrataand structures posterior to it, an anterior segment 200 including anarea corresponding to the pars plana and the structures anterior to it.A corneal rim 210 and iris 212 are visible upon an exterior surface ofanterior segment 200. Posterior segment 110, forming the globe 128, isconnected to base 102 by one or more rectus muscles 114. An optic nerve116 extends from the posterior segment to base 102. It should beunderstood that the boundary between the posterior and anterior segments110, 200 can be different, for example, the ora serrata or otherstructure can be included in anterior segment 200. However, as describedfurther elsewhere herein, the interior of the globe portion of the eyecan be filled with a vitreous component which is conveniently retainedin the posterior segment.

With additional reference to FIGS. 5-7, the posterior segment includesthe retinal fundus and associated structures, including the retina,optic disc, vasculature/arcade, and macula, which may be formed in partas a separate, removable fundus part 112 as shown in dashed lines inFIG. 2, and in FIGS. 7, and 11, or may be removable but integrallyformed by 3D printing during fabrication of anterior portion 110, oralternatively may be formed integrally with a posterior portion of theeye. Structures visible at the back of the eye, such as the macula,retinal vasculature, and optic disc, can be printed during 3D printerfabrication onto removable fundus part 112, or can be printed directlyonto a fundus location of the eye where part 112 is integral, or may beseparately printed onto a flexible substrate 122 (FIG. 7), which issecured in place after 3D printing.

As shown in FIG. 2, and with reference to FIGS. 8-10, an optical elementor lens 250 is inserted within anterior segment 200 to lie betweenstructures resembling suspensory ligaments and ciliary bodies 202(visible in FIGS. 8-9). Lens 250 can be provided with a focal lengthwhich approximates that of the particular eye the model is replicating,for example that of a human eye. Lens 250 includes a posterior ridge 252which is provided to seat the lens within at location with respect tothe retina which approximates that of the eye. A corresponding matingannular groove or ridge 204 is provided within anterior segment 200. Dueto a flexibility of anterior segment 200, corresponding to the naturalresiliency of the body, mating ridge 204 can be sized to form aninterference fit with posterior ridge 252, and therefore resilientlygrips posterior ridge 252 when the latter has been inserted into matingengagement with mating groove 204. In this manner, lens 250 is insertedinto mating engagement by being inserted through the interior portion ofanterior segment 200, as shown by the dashed arrow of FIG. 2. Lens 250is advantageously handled using gloves, to avoid introducingfingerprints or other markings onto lens 250.

It should be understood that, alternatively, anterior segment 200 can beprovided with a ridge and lens 250 can be provided with a groove, orthat any other kind of dovetail or interlocking engagement can be formedbetween the anterior segment 200 and lens 250, including for examplethreaded engagement. Alternatively or additionally, the ciliary bodies202 or processes can be formed to partially interfere with passage oflens 250 into a final position, and to retain lens 250 in position. Assuch, lens 250 can be pushed past such interference by pressing aboutthe periphery of the lens.

In the embodiment illustrated, lens 250 is dimensioned to form both thelens and the cornea, although these can be provided as separatestructures, if desired. If provided as separate structures, an iris canbe provided to be positioned between the lens and cornea, or canalternatively be provided behind the combined lens and cornea to rendera similar effect.

Anterior segment 200 is provided with an annular peripheral flange orridge 206 which matingly engages a corresponding annular groove 106formed within an anterior portion of posterior segment 200. Posteriorsegment 110 is printed to have a resilient property similar to the eye;as such, groove 106 can be elastically stretched to admit passage ofridge 206. It should be understood that, alternatively, anterior segment200 can be provided with a groove and posterior segment 110 with aridge, or that any other kind of dovetail or interlocking engagement canbe formed between the anterior and posterior segments 200, 110,including for example a threaded engagement.

One or more of the muscle attachments 118 additionally overlap anteriorsegment 200. More particularly, in one embodiment, muscle attachments118 are fixed to posterior segment 110, and retain anterior segment 200anteriorly by projecting anteriorly and inward to extend past and overthe anterior segment. In this manner, a retaining or a clamping force isapplied between the anterior and posterior segments 110, 200, so that aseal can be maintained between anterior and posterior segments 110, 200.This enables not only removal of anterior segment 200, but replacementof anterior segment 200 as needed. For example, anterior segment can bepierced by trocars, as described elsewhere herein, and may eventuallyneed to be replaced for this or other reasons, which is facilitated bythe releasable connection formed by the seal between annular ridge 206and annular groove 106, and the cooperating engagement of one or moremuscle attachments 118, as described above.

As shown in FIG. 3, once lens 250 has been assembled into anteriorsegment 200, and anterior segment 250 has been assembled into posteriorsegment 110, the fundus and associated structures can be viewed bylooking through lens 250.

As lens 250, anterior segment 200, and posterior segment 110 can beindependently replaced, device 100 forms a platform that is reusable,where parts subject to wear or damage can be replaced as needed, andwhere lesser affected parts can continue to be reused.

With reference to FIG. 11, device 100 can be used to train a surgeon toremove a thin film from a surface of the interior of the eye. One suchexample is Internal Limiting Membrane (ILM) peeling. In accordance withthe disclosure, a coating 304 (FIG. 13) is applied to the retinalsurface. In the embodiment shown, the coating is applied using a roll-onapplicator 300, although other methods can be used, including brush orspray applicator. In order to provide for quick drying, a volatilesolvent can be mixed with the coating to maintain the coating in aliquid state within the dispenser, and while dispensing. As the solventevaporates, the coating dries and adheres to the substrate, which in theexample shown is retinal part 112. Once the coating has applied, thesolvent will evaporate over time, or a stream of air can be directedagainst the coating to hasten drying. Once the coating has dried, it isready to be peeled from the eye in a mock surgical procedure.

Any coating material can be used which has properties resemblingnaturally occurring membranes which are desired to be removed. Suchproperties include an adhesion to the retinal or other surface of theeye which is sufficiently weak to allow peeling without damage to theunderlying structure. Additionally, the dried coating must besufficiently cohesive as to be peelable in strips, as occurs within thebody. Such a coating material can be produced combining any substratematerial, such as a cellulosic or polymeric material, with a solventwhich renders or maintains the substrate material in liquid form, andwhich exhibits the desired properties when present in the eye. One ormore dyes or colorants can be added to the base coating, in order tosimulate either a typical color of naturally occurring membranes, or anyof the various dye colorings used in such surgical peeling procedures.

For clarity, part 112 is illustrated as removed from posterior segment110. As a practical matter, there is no need to remove part 112 to applythe coating, as roll-on applicator 300 can be readily manipulatedagainst the retinal surface after having removed only the anteriorsegment 200. A spiral arrow is illustrated in FIG. 11 to demonstratethat it is typically desired to apply the coating evenly over thesurface, to mimic the natural growth of undesired membranes. Any patternof application can be used, however, and overlapping can be carried outto increase a thickness of all or a portion of the applied coating. Anoverlap or thicker region relative to surroundings can be deliberatelyformed, for example, in order to facilitate an initial grasp of themembrane for peeling, during training. Irregularities can alternativelybe formed by applying bursts of air, for example using compressed airfrom a spray can. To apply a thicker coating, a cotton swab may be usedinstead of a roll-on applicator.

The coating may be removed by using a cotton swab moistened with wateror a solvent, and the fundus can be dried, for example in preparationfor applying a new coating, by the application of a jet of air.

The foregoing coating can additionally be removed by the application oflaser light energy, for example, and a coating can be selected whichresponds to the application of laser light in a manner similar tomaterials removed by laser in actual therapeutic practice.

As shown in FIGS. 12-13, a trocar or other piercing instrument can beused to insert a portal in a surface of the eye, through which forceps310 or other instrument may be passed, and through whichseparated/peeled membrane (coating), or other objects, can be removedfrom the eye. Additional ports may be provided for other instruments, asdescribed with respect to vitreous replacement, and as shown in FIG. 16.

In FIGS. 14A-14B, anterior segment 250 is assembled onto posteriorsegment 110. As shown, anterior segment 250 is at first inserted undertwo opposing muscle attachments 118 (FIG. 14A), and then moved laterallyuntil it is positioned under three muscle attachments 118 (FIG. 14B).The final muscle attachment 118 can be pried from under anterior segment250 with a slim object, such as a plastic spudger, or a curved-endedtool 312 as shown, which is turned over from the view shown, insertedbetween the remaining muscle attachment 118 and anterior segment 250,and rotated end-over-end to move the muscle attachment over anteriorsegment 250. Once this has been accomplished, peripheral ridge 206 maybe pushed downward to be inserted into groove 106 of posterior segment110.

To facilitate insertion, ridge 206 and/or groove 106 can be lubricatedwith a peripheral bead of viscoelastic sealant, which may or may notadditionally have a lubricating property, water, or other sealant whichis not harmful to the materials forming device 100. Dispersiveviscoelastics are made by variety of manufacturers, particularly in theeye care field. The use of viscoelastic seal is advantageously helpfulin ensuring a liquid tight seal between posterior segment 110 andanterior segment 250, avoiding a requirement for a threaded seal, or theuse of o-rings or other gasket. Other sealant materials includesilicones, caulking, petroleum jelly, sealing grease, and a weakadhesive that is releasable without damaging the sealed components.

As shown in FIG. 14C, the fourth muscle insertion can be more easilymoved above anterior segment 200 by gently squeezing globe 128 toelongate the globe along an axis passing through the fourth muscleinsertion 118. This technique can be used to carry out assembly withoutthe use of a tool.

To disassemble anterior segment 250 from posterior segment 110, lens 250is first pushed into the interior of the globe. Next, the anteriorsegment is grasped by inserting one finger through the aperture openedby removal of the lens, and pinching the anterior segment between twofingers, whereupon it may be pulled away from and free of posteriorsegment 110. Alternatively, a tool can be provided which includesrounded or soft ends, which can be inserted through the iris and leveredagainst the inside of anterior segment 250 to cause separation ofanterior segment 250 from posterior segment 110.

Referring now to FIGS. 15-16, device 100 may be filled with a vitreoussubstance which is similar in appearance and opacity, and viscosity, tonaturally occurring vitreous humor for the type of eye being simulated.A convenient material is egg whites from a chicken egg, or materialshaving similar appearance and viscosity to egg whites, including anyother material which is advantageously not harmful to the materials fromwhich device 100 is fabricated. As shown, a syringe 322 may be used todraw up egg whites from a containment vessel, and to load the egg whitesinto the eye. As shown, anterior segment 250 is removed to expose theeye interior. In an embodiment sized to represent a human eye, about 3cc of egg whites are used, although different amounts can be useddependent upon the size of the interior of device 100, to correspond tofilling of a natural eye. Care is taken to introduce the vitreoussubstitute slowly, to avoid introducing bubbles. If bubbles do form,they may be aspirated to remove them before replacing the anteriorsegment as described herein.

As shown in FIG. 16, a surgical procedure can be carried out usingdevice 100, which procedure is more realistic once a vitreous substancehas been added to the eye. In particular, a vitrectomy can be performed,to remove all or a portion of the vitreous substitute. As shown, threeports 320 have been formed, including a port 320 each for admitting aninstrument for illumination 314, an injection instrument 316 tointroduce air or liquid to maintain internal eye pressure, and a cutteror aspirator instrument 318 to remove the vitreous humor/substitute, orother material or object from the eye. Other procedures which may besimulated include, but are not limited to, addressing retinaldetachment, macular pucker, diabetic retinopathy, macular holes,vitreous hemorrhage, and vitreous floaters. As needed, objects can bedeliberately introduced into the eye, together with the vitreoussubstitute, to enable training for certain procedures. Such procedurescan be facilitated by the application of retro-illumination throughglobe 128.

In an embodiment of the disclosure, globe 128 is at least partlytranslucent, enabling light transmission, and retro-illumination. AnIris of any desired size can be produced, for example between 1 and 8mm, and lens 250 can be provided in various optical powers, with variouscoatings. Additionally, the fundus can be printed with variouspathologies, or a plurality of flexible substrate 122 can be provided,each illustrating a different pathology. In an embodiment, lens 250 hasan optical power between 40 and 60 diopters, although a larger orsmaller range can be used, dependent upon the optical power of thenatural eye which is being simulated, or a power selected to facilitatesimulating surgery with device 100.

Accordingly, the disclosure provides a simulation and model, device 100,for anterior and posterior segment training and simulation. Device 100facilitates training in basic retinal examination technique andinstrumentation such as indirect ophthalmoscopy, slit-lamp, contact andnon-contact retinal lenses, and retinal cameras. It is also an usefultool for demonstration, practice and assessment of retinal instrumenthandling and microscope skills such as use of surgical contacts lenses,non-contact systems and inverters. The modular design of device 100allows insertion of foreign bodies or vitreous substitutes to enhancetraining scenarios. It also allows simplifications such as opticalelement removal and trans-illumination to facilitate practice wherevitreo-retinal equipment is unavailable.

All references cited herein are expressly incorporated by reference intheir entirety. It will be appreciated by persons skilled in the artthat the present disclosure is not limited to what has been particularlyshown and described herein above. In addition, unless mention was madeabove to the contrary, it should be noted that all of the accompanyingdrawings are not to scale. There are many different features to thepresent disclosure and it is contemplated that these features may beused together or separately. Thus, the disclosure should not be limitedto any particular combination of features or to a particular applicationof the disclosure. Further, it should be understood that variations andmodifications within the spirit and scope of the disclosure might occurto those skilled in the art to which the disclosure pertains.Accordingly, all expedient modifications readily attainable by oneversed in the art from the disclosure set forth herein that are withinthe scope and spirit of the present disclosure are to be included asfurther embodiments of the present disclosure.

What is claimed is:
 1. A device for simulating surgery upon the eye,comprising: a posterior segment including: structures corresponding tothose of the eye, including a hollow globe and an image of the funduspositioned upon an interior, posterior portion of the globe; and a firstmating portion peripherally formed about an open end of the globe; ananterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens positionable within the opening; a second matingportion peripherally formed about a posterior portion of the anteriorsegment, the second mating portion mateable with the first matingportion to releasably connect the posterior and anterior segments; athird mating portion peripherally formed about the lens; and a fourthmating portion peripherally formed about the opening, the fourth matingportion mateable with the third mating portion to releaseably connectthe lens and the anterior portion.
 2. The device of claim 1, wherein thefirst, second, third, and fourth mating portions are dovetail portions.3. The device of claim 1, further including a plurality of rectusmuscles each attached to the globe at attachment points.
 4. The deviceof claim 3, one or more of the plurality of rectus muscles overlappingthe anterior segment to retain the anterior segment in mating connectionto the posterior segment.
 5. The device of claim 3, further including abase, the base attached to the plurality of rectus muscles.
 6. Thedevice of claim 1, wherein the globe is at least partially opticallytransparent.
 7. The device of claim 1, wherein the lens is releasablyretained between the third mating portion and a structure resemblingciliary bodies.
 8. The device of claim 1, wherein the device isfabricated using a multi-material 3D printing process.
 9. The device ofclaim 1, further including a removable coating that is applyable to aninterior of the posterior segment.
 10. The device of claim 9, whereinthe coating is a liquid which is applyable to the image of the fundus toform a film that will adhere to the fundus when dried, and after dryingis peelable from the fundus in strips.
 11. The device of claim 9,wherein the coating includes a substrate and a volatile solubilizingagent.
 12. The device of claim 9, wherein the coating is containedwithin a roll-on applicator.
 13. A method of enabling simulation oftherapeutic procedures performed upon the eye, comprising: providing aposterior segment including: structures corresponding to those of theeye, including a hollow globe and an image of the fundus positioned uponan interior, posterior portion of the globe; and a first mating portionperipherally formed about an open end of the globe; providing ananterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens positionable within the opening; a second matingportion peripherally formed about a posterior portion of the anteriorsegment, the second mating portion mateable with the first matingportion to releasably connect the posterior and anterior segments; athird mating portion peripherally formed about the lens; and a fourthmating portion peripherally formed about the opening, the fourth matingportion mateable with the third mating portion to releaseably connectthe lens and the anterior portion; providing a coating which isapplyable to the fundus to form a film that will adhere to the funduswhen dried, and after drying is peelable from the fundus in strips. 14.The method of claim 13, wherein the coating provided includes asubstrate and a volatile solubilizing agent.
 15. The method of claim 13,further including providing instructions for applying the coating to theposterior segment.
 16. The method of claim 14, wherein the substrate isselected from a cellulosic and a polymeric material.
 17. The method ofclaim 13, further including providing a vitreous substitute material tobe placed inside the posterior segment.
 18. The method of claim 13,further including providing instructions for inserting a vitreoussubstitute material into the posterior segment.
 19. The method of claim13, further including providing a viscoelastic substance to be depositedbetween the first and second mating portions, the substance operative tocreate a temporary liquid-tight seal.
 20. A method of simulating asurgical procedure upon the eye, comprising: separating an anteriorsegment of a simulated eye from a posterior segment segment of asimulated eye, the posterior segment including: structures correspondingto those of the eye, including a hollow globe and an image of the funduspositioned upon an interior, posterior portion of the globe; and a firstmating portion peripherally formed about an open end of the globe andhaving the form of one of an annular groove and annular flange; theanterior segment including: structures corresponding to those of theeye, including a pars plana, an opening in a region corresponding to aniris, and a lens; a second mating portion peripherally formed about aposterior portion of the anterior segment, the second mating portionmateable with the first mating portion to releasably connect theposterior and anterior segments, the second mating portion having theform of an annular groove if the first mating portion is an annularflange, and an annular flange if the first mating portion is an annulargroove; inserting a vitreous substitute material into the posteriorsegment, the substitute material resembling the viscosity and appearanceof vitreous humor of a natural eye; and simulating a surgical procedureincluding removal of vitreous substitute from the eye with the posteriorand anterior segments assembled together.
 21. The method of claim 20,further including, prior to inserting a vitreous substitute, applying acoating to a portion of the image of the fundus; and simulating asurgical procedure including peeling of the coating with the posteriorand anterior segments assembled together.